Why does the earth receive different amount of sun and light?

Answer 1

1. The main thing to keep in mind is that the earth is like a huge ball, a globe in the sky.

2. Now imagine the sun is directly over a particular place on the earth. If you block the sun with a disk that is 1 ft in diameter, on the surface of the earth you will see a shadow of the disk. The shadow will be a circle that will also be 1 ft in diameter. This shadow shows the area the sun's energy would have received if the disc wasn't there.

3. But if the sun is shining at an angle, which it does in the morning or evening, and which it does in wintertime, and you then block the sun with that same 1 ft disk, the shadow on the ground will be bigger, possibly much bigger. It will still be 1 ft wide, but it will have a long elliptical shape. This bigger shadow shows the larger area that any given 'amount per minute' of the sun's energy that would have reached if the disc wasn't there.

So, if the same amount of 'energy per minute' from the sun is now radiating onto an area twice as big, then the amount of energy reaching each square inch per minute will be halved, and it will be cooler!

This is why it is cooler at the beginning and end of the day, and cooler in summer than in winter.

In the same way, on a grand scale, when the sun is directly overhead at midday, for example, at the equator (0o latitude), or between the tropics of Cancer and Capricorn (latitude 23.43o), then the maximum amount of the sun's energy 'per square foot per minute' is reaching the surface of the earth, and it will be at its warmest/hottest.

But the further away from the tropics you go, sloping away, say, to latitude 40o (e.g. Italy) or 65o (Iceland) then the energy from the sun can only strike the earth's surface at an angle, thus spreading the 'energy per minute' over more square feet. The heat/light will be less per square foot, and the surface of the earth at those places will consequently be cooler than the temperature of the earth's surface where the 'energy per minute' comes from directly overhead and thus onto a smaller area.

Answer 2

The main factor that influences the amount of energy that different places on Earth receive from the sun is the places location. The closer it is to the equator the more sun energy it will receive.

Answer 3

Because of the earth's round shape the equator, is closest to the sun and the closer you get to the earths poles, you get further and further from the sun.

Plus, since every location is unique, every location gets a unique solar energy intake.

Answer 4

It is because the Earth wobbles and tilts while orbiting the Sun. When the North Pole is tilted towards the Sun the northern hemisphere enters summer time and enjoy more light and heat. The Southern Hemisphere will then enter their winter period. Eventually, as the seasons pass, the Earth will reverse the tilt, and the northern hemisphere enters their winter. It is all about the angle that sunlight falls on the Earth.

Answer 5

The amount of solar radiation reaching the earth's surface varies greatly because of changing atmospheric conditions and the changing position of the sun, both during the day and throughout the year. Clouds are the predominant atmospheric condition that determines the amount of solar radiation that reaches the earth. Consequently, regions of the nation with cloudy climates receive less solar radiation than the cloud-free desert climates of the southwestern United States. For any given location, the solar radiation reaching the earth's surface decreases with increasing cloud cover.

Local geographical features, such as mountains, oceans, and large lakes, influence the formation of clouds; therefore, the amount of solar radiation received for these areas may be different from that received by adjacent land areas. For example, mountains may receive less solar radiation than adjacent foothills and plains located a short distance away. Winds blowing against mountains force some of the air to rise, and clouds form from the moisture in the air as it cools. Coastlines may also receive a different amount of solar radiation than areas further inland. Where the changes in geography are less pronounced, such as in the Great Plains, the amount of solar radiation varies less.

The amount of solar radiation also varies depending on the time of day and the season (see Understanding Seasonal and Atmospheric Variations .) In general, more solar radiation is present during midday than during either the early morning or late afternoon. At midday, the sun is positioned high in the sky and the path of the sun's rays through the earth's atmosphere is shortened. Consequently, less solar radiation is scattered or absorbed, and more solar radiation reaches the earth's surface. In the Northern Hemisphere, south-facing collectors also receive more solar radiation during midday because the sun's rays are nearly perpendicular to the collector surface. Tracking collectors can increase the amount of solar radiation received by tracking the sun and keeping its rays perpendicular to the collector throughout the day. In the Northern Hemisphere, we also expect more solar radiation during the summer than during the winter because there are more daylight hours. This is more pronounced at higher latitudes.

Both man-made and naturally occurring events can limit the amount of solar radiation at the earth's surface. Urban air pollution, smoke from forest fires, and airborne ash resulting from volcanic activity reduce the solar resource by increasing the scattering and absorption of solar radiation. This has a larger impact on radiation coming in a direct line from the sun (direct beam) than on the total (global) solar radiation. Some of the direct beam radiation is scattered toward earth and is called diffuse (sky) radiation (global = direct + diffuse). Consequently, concentrators that use only direct beam solar radiation are more adversely affected than collectors that use global solar radiation. On a day with severely polluted air (smog alert), the direct beam solar radiation can be reduced by 40%, whereas the global solar radiation is reduced by 15% to 25%. A large volcanic eruption may decrease, over a large portion of the earth, the direct beam solar radiation by 20% and the global solar radiation by nearly 10% for 6 months to 2 years. As the volcanic ash falls out of the atmosphere, the effect is diminished, but complete removal of the ash may take several years.

-SHINING ON-

Answer 6

depends on the angle at wich the sun rays are hittng that particular spot